Transpiration and Stomata

Question 1

What is the transpiration rate affected by

Answer 1

• Light intensity
• temperature
• Airflow`
• humidity

Question 2

How does light intensity affect the transpiration rate

Answer 2

the brighter it is, the greater the transpiration rate. The stomata closes at night as photosynthesis can’t happen so no co2 comes in. So when the stomata closes, not much water can escape

Question 3

Hoes does temperature affect the transpiration rate

Answer 3

The warmer it is, the faster transpiration happens. This is because the particles have more energy to evaporate and diffuse out of the stomata

Question 4

How does air flow affect the transpiration rate

Answer 4

The better the airflow is, the greater the transpiration rate. If the airflow is bad, the water vapor doesn’t go away as the diffusion is bad causing a high concentration of water outside the leaf compared to inside. If the airflow is good the water vapor is swept away so there is a low concentration of water particles outside the leaf to inside

Question 5

How does humidity affect the transpiration rate

Answer 5

The drier the leaf, the faster the transpiration rate. The air is humid so there isn’t much of a difference in concentration in water vapor outside the leaf compared to inside.

Question 6

What do guard cells do

Answer 6

open and close the stomata

Question 7

What happens when the guard cells open and close

Answer 7

when the plant opens, the guard cell fills with water and becomes plump and turgid, and opens the stomata so gases can be exchanged for photosynthesis

when the plant is short for water the guard cells become flaccid and close to stop too much water from escaping

they are sensitive to light so they close at night